An update on QCD+QED simulations with C* boundary conditions

Abstract

We present two novelties in our analysis of fully dynamical QCD+QED ensembles with C* boundary conditions. The first one is the explicit computation of the sign of the Pfaffian. We present an algorithm that provides a significant speedup compared to traditional methods. The second one is a reweighting of the mass in the context of the RHMC. We have tested the techniques on both pure QCD and QCD+QED ensembles with pions at $m_{\ddot{I}{€}^{\pm }}\approx 400$ MeV, a lattice spacing of $a\approx 0.05$ fm, a fine-structure constant of $\hat{I}{\pm }_{\mathrm{R}}=0$ and $0.04$.

RC* Collaboration, Lattice 2021